Dr. Fusen worked as a scientist for the Melkian military. He specialized in genetic engineering research and development, contributing directly to the clandestine Perfect Soldier project aimed at creating enhanced soldiers with superior physical and combat capabilities through genetic manipulation.
He collaborated closely with Captain Jean Paul Rochina, the high-ranking officer overseeing the project's military applications. Dr. Fusen's expertise was key in creating and refining Fyana (Prototype #1), one of the Perfect Soldiers. His duties included monitoring Fyana's physiological stability, psychological conditioning, and overall combat readiness as a vital military asset.
Dr. Fusen operated within the project's secure facilities under military jurisdiction, representing the scientific arm of the Melkian military's pursuit of advanced warfare technology via human enhancement. The character appears in multiple episodes within the series narrative focused on the pursuit of Chirico Cuvie and the secrets surrounding Fyana's origins.